In the past, many people tried to invent a safety control system with automatic induction and automatic braking functions or to invent other car safety control system. However, it was the brake control technique in which they failed to carry out their ideas because that cars already available on the market are not designed to be additionally installed with the brake control device. Moreover, various cars are fashioned with different shapes. Thus, it is very difficult and can hardly be practiced to invent a small brake machine which is suitable to be mounted on various cars easily. For example, the brake design in G. M. Gary's automobile controls of U.S. Pat. No. 2,385,928 is so big and complex that it can't be installed in the car available on the market. Even newly designed cars won't use such a big complicated brake design as the automobile control. Therefore, it remains unpractical at present. Yet, this invention, a product of several years' research, can solve the above problems and achieve object of controlling braking and avoiding bump.